1. Technical Field
The present invention relates to a sampling circuit and a sampling method, and in particular, to a sampling circuit and a sampling method capable of dynamically regulating a delay.
2. Related Art
Please refer to FIG. 1, in which a memory module 10 includes a dynamic random access memory (DRAM) 12 and a controller 14. The controller 14 accesses the DRAM 12 using a data signal DQ and a data strobe signal DQS.
Generally speaking, the memory module 10 is designed to provide a fixed delay to delay the data signal DQ and/or the data strobe signal DQS, so as to achieve the optimum efficacy of controlling the memory module. However, after the memory module 10 has been fabricated in the factory, the fixed delay cannot be dynamically changed any more.
Nevertheless, a phase of the data signal DQ and that of the data strobe signal DQS may fluctuate due to noise, or inner/outer environment changes such as a process-voltage-temperature (PVT) change, thereby deviating from a preset delay. It is therefore difficult for the memory module 10 to achieve the optimum efficacy using the fixed delay.